Ultra-broadband and flexible metamaterial absorber based on MoS2 cuboids with Mie resonances

In this work, we present a type of flexible and broadband metamaterial absorber operating in the GHz range. The proposed structure consists of three layers: a periodic square-shaped array made of molybdenum disulfide (MoS2) on the top, a continuous polyimide layer in the middle and a continuous copper layer at the bottom. For flat model, the proposed absorber exhibits a broadband absorption in the frequency range of 10.1-17.6 GHz with an absorption of more than 90% under normal incidence. Due to the symmetry of structure, the absorption feature is polarization-insensitive. The absorption remains above 80% in the frequency range of 11.1-15.6 GHz when the incident angle is up to 60 degrees for TE-polarized wave, while the absorption is higher than 90% in the frequency range of 13.5-18 GHz for incident angles up to 60 degrees for TM-polarized wave. For bending model, the absorption is significantly expanded when the bending radius decreases to under 100 mm. The physical mechanism of the absorption properties is explained in detail by the electric field distribution, the magnetic field distribution following the Mie resonance theory and influence of the loss of MoS2. Obtained results in the work might contribute to the development of potential applications based on metamaterials in the microwave region such as imaging, protecting and light emitting devices.